DESCRIPTION: The long-term objective of the proposed study is to develop GES into a viable alternative therapy for non obstructive gastroparesis. Unlike in the heart and skeletal muscles, the feasibility of therapeutic electrical stimulation in the GI tract remains unproven. The mechanism of action and value of parameters essential for efficient gastric stimulation in patients are unknown and cannot be safely or ethically determined in humans. The specific aims of this study are to: i) determine the feasibility of electrical stimulation as a prokinetic agent in the stomach, and ii) establish the parameters that are important in bringing it about. The research design employs an analytical model and computer simulation and a canine model of stimulation in the stomach. GES will be carried out over a range of frequencies, pulse-widths, and amplitudes in vivo in dog stomach implanted with electrodes and strain gauges (with and without vagotomies). By evaluating the electrical response (as measured by electrodes), contractile response (as measured by strain gauges), and gastric emptying (as measured by radio-nuclide scintigraphy) to the stimulating current, optimum parameters for stimulating the stomach will be determined. Histological studies will be performed on biopsied tissue to study fibrosis formation at the electrode-tissue interface, and its effect on stimulation efficiency. Simultaneously, an analytic model of the entrainment of native gastric electrical activity (GEA) by an externally supplied electrical stimulus will be developed and simulated on a computer. The model will be employed in analyzing GES and predicting what pattern of stimulation is required to entrain GEA in different disease conditions.